Back in the days of Xcode 6 this was everything you had to do; just specify the format to be ipa
and set the required paths and the Provisioning Profile to be used for code signing the ipa.

Xcode 7 introduced a lot of additional archive feature and the support for
defining more complex archive parameters. This meant that although Xcode 7 still supports
the old parameters, it's now declared as deprecated, and you'd get
the following warning if you'd use the old parameters instead of the new -exportOptionsPlist parameter:

The export command's new version expects a Plist file (-exportOptionsPlist),
which should include all the archive parameters (including code signing type/method,
and other parameters like enable/disable Bitcode). The full command looks like this:

By default the Xcode Archive step generates the minimal sufficient Plist file,
with only the export method defined in it (unless you specify the export_options_path input,
we'll get back to this a bit later):

The default generated export options Plist file only specifies
the export method (app-store, ad-hoc, enterprise or development)
based on the provisioning profile embedded in the .xcarchive (which is generated by the xcodebuild archive
command, also performed by the Xcode Archive step, right before the xcodebuild -exportArchive command).

The embedded provisioning profile depends on your code sign settings in your project.
You can force the desired code signing configuration
with Xcode Archive step's force_code_sign_identity and force_provisioning_profile inputs.
You can find more information about these options in the iOS Code Signing article.

Every other export option which can be defined in the Plist is optional.

In case of the default export_options.plist does not fit your needs,
you can specify your own export options too.
To do this create a plist file (in your repository) with the options you want to use.

Available export options

You can get a list of all available options by calling xcodebuild -h -
check the Available keys for -exportOptionsPlist: section of the printed help.

These are the options you can select in Xcode when you export the ipa manually.

The recommanded way is to put this generated plist file in your project's repository.
Then you can set Xcode Archive step's export_options_path input
to the path of your plist file (e.g. ./path/to/export-options.plist).

By default uploadBitcode export options is set to YES, unless you specifically disable
it in the export options Plist.
If it does not fit your requirements you have to use your own export options,
instead of the archive steps generated one.